Spider Climb. The spider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Web Sense. While in contact with a web, the spider knows the exact location of any other creature in contact with the same web.

Web Walker. The spider ignores movement restrictions caused by webbing.

Multiattack. The dragon makes one Bite attack and two Claw attacks.

Bite. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 8 (1d10 + 4) piercing damage, and the target must make a DC 15 Constitution saving throw, taking 22 (5d8) poison damage on a failed save, or half as much damage on a successful one. If the poison damage reduces the target to 0 hit points, the target is stable but poisoned for 1 hour, even after regaining hit points, and is paralyzed while poisoned in this way.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) slashing damage.

Spider Breath (Recharge 5–6). The dragon exhales dozens of tiny spiders up to 30 feet away. Summon 3 (1d6) Swarm of Insects (Spiders) in an unoccupied space within range.